This invention relates generally to remote proximity measuring devices and more specifically to light-operated proximity measuring devices.
It is well-known that with a point light source or an incident collimated light beam reflecting from a target surface, the light intensity is proportional to the square of the inverse of the distance. Light transducers used to detect light provide a voltage output proportional to the intensity of the incident light. In the past, it has been necessary to provide a computer or other hardware to make required complex calculations in order to translate this nonlinear voltage into a calibrated distance. Further, because of high thermal drift, measurements made in this manner are rarely reproducible.
Thus, there is a need to provide a light-operated proximity detector which provides direct translation of incident reflected light intensity from a surface into a signal which is directly proportional to the distance without the complex calculations normally required with light-operated proximity detectors.